How hair loss treatments work
Plain-English explainers for the two medications behind every modern hair loss plan, and why combining them is usually better than either alone.
The basic problem we're fixing
In male and female pattern hair loss (androgenetic alopecia), the issue isn't that hair stops growing. The issue is that follicles in genetically susceptible scalp areas shrink: each growth cycle produces a slightly finer, slightly shorter hair, until eventually the follicle stops producing visible hair at all.
The hormone driving that shrinkage is dihydrotestosterone (DHT), a downstream product of testosterone. Modern hair loss treatment attacks the problem from two angles: lowering DHT to stop the damage, and pushing the surviving follicles to grow harder.
Those two angles are what finasteride and minoxidil do, respectively.
Finasteride
Stop DHT being made in the first place
Finasteride is a once-daily oral tablet that blocks the enzyme 5-alpha reductase. That enzyme is what converts testosterone into DHT. Block the enzyme, you get less DHT, and the follicle shrinkage that DHT causes slows down or reverses.
Around 80% of patients on finasteride stabilise their hair loss within twelve months, and a meaningful proportion (approximately 48% at 12 months and 66% at 24 months in the Kaufman 1998 trial) see visible regrowth. The effect builds slowly: most people see stabilisation by month three and visible improvement by month six.
Side effects require honest discussion at clinical review. Sexual side effects (reduced libido, erectile dysfunction, ejaculation disorders) and mood changes (low mood, anxiety, depression and rarely suicidal thoughts) have been reported. The MHRA Drug Safety Updates on finasteride (29 April 2024 and 11 May 2026) introduced patient alert cards into finasteride packs and recognise that sexual dysfunction may persist after discontinuation in a small number of cases. The 2026 update extended precautionary advice to dutasteride. Your clinician will walk you through the full picture before prescribing, and you should stop and seek advice if any of these effects occur. Finasteride is not licensed for women and must not be handled (as a crushed or broken tablet) by women who are or may become pregnant.
How it works
How it works
Minoxidil
Push the follicle to grow harder, longer
Every hair follicle cycles through three phases: a long growth phase (anagen), a short transition phase (catagen), and a resting phase (telogen) where the hair eventually sheds. In pattern hair loss, the growth phase gets shorter each cycle, so hairs are finer and don't grow as long before they fall.
Minoxidil extends the growth phase and may also improve blood flow to the follicle. The full mechanism is still being studied but the clinical evidence is strong: most patients on combination finasteride + minoxidil see meaningfully better results than either alone.
Available as a topical solution applied to the scalp daily, or as a low-dose oral tablet. The oral form is prescribed off-licence in the UK for hair loss (its licensed use is for high blood pressure) but is supported by a growing evidence base and has improved adherence for many patients who struggle with the topical. Your clinician will explain the options, including off-licence status, and recommend the right form for you.
Why we usually combine them
Finasteride and minoxidil attack the problem from completely different angles. Finasteride stops the damage being done. Minoxidil makes the surviving follicles grow harder. Together they cover both halves of the equation.
Trial data and clinical experience both show that combination therapy produces meaningfully better results than either alone for most patients with androgenetic alopecia. It's the regimen we typically build into the Advanced plan, and the one most patients on the Essentials plan upgrade to after seeing how things respond.
There are situations where we prescribe only one (or neither). A clinical review is the only way to know what's right for your case.
A note on side effects. Both medications have well-documented side-effect profiles. The vast majority of patients tolerate them without issue, but a small minority experience side effects that warrant adjusting or stopping treatment. Your clinician will discuss the full picture honestly at clinical review , informed consent is part of the standard of care.